public class myTest {
    public static void main(String[] arg) {
        String s = "f";

        boolean b = Boolean.valueOf("true").booleanValue();
        System.out.println(b);

        boolean b1 = Boolean.valueOf(s).booleanValue();
        System.out.println(b1);

        boolean b2 = Boolean.parseBoolean(s);
        System.out.println(b2);

        Boolean bb = new Boolean(s);
        boolean b3 = bb.booleanValue();
        System.out.println(b3);
    }

}
